2 literature references for Stelligera stuposa rigida (Montagu, 1818):

Author: Montagu, G.
Year: 1818
Title: An Essay on Sponges, with Descriptions of all the Species that have been discovered on the Coast of Great Britain.
Source: Memoirs of the Wernerian Natural History Society 2(1): 67-122,pls III-XVI.
Author: Descatoire, A.
Year: 1969
Title: Les peuplements sessiles de l’Archipel de Glénande l’infralittoral rocheux. II. - Notes systématiques à propos de l’inventaire des Spongiaires.
Source: Vie et Milieu (A, Biologie Marine) 20(1-A): 9-30.